Short-term Efficacy Of Unicompartmental Knee Arthroplasty For Unicompartmental Knee Osteoarthritis In Combination With Coronal Tibiofemoral Subluxation Of The Knee

Objective:To investigate the effects of varying levels of pre-operative Coronal tibiofemoral subluxation(CTFS)on post-operative outcomes of patients after unicompartmental knee arthroplasty(UKA).Methods:From June 2017 to June 2018,a total of 115 patients with medial knee osteoarthritis who underwent unicompartmental knee arthroplasty were retrospectively analyzed.According to the CTFS measured on preoperative anteroposterior knee radiographs,the patients were divided into two groups(group A and group B).There were 32 patients with preoperative CTFS≥0.5cm in group A,including 7 males and 25 females.And Patients with preoperative CTFS < 0.5 cm were in group B,with 83 cases,including 30 males and 53 females.Two groups of patients underwent unicompartmental knee arthroplasty by the same operator.The CTFS,Oxford knee score(OKS),and range of motion(ROM)of the two groups were compared after UKA.Results:The preoperative CTFS of group A was 0.63±0.09 cm,which was significantly larger than that of the group B(0.22±0.19 cm)(t = 11.57,P < 0.0001).The preoperative ROM of group A was(111.3±12.4)°,which was significantly larger than that of the group B(106.9±7.7)°,(t = 2.03,P =0.04),but No statistically significant difference was observed between the two groups for the preoperative OKS(t=1.81,p=0.07).At 6-month follow-up,the CTFS of group A were 0.29±0.20 cm,which was statistically significantly reduced compared to the preoperative CTFS of group A(t = 8.85,P < 0.0001).However,the CTFS of group B were 0.22±0.22 cm and No significant statistical difference was found in preoperative and postoperative CTFS of group B(t = 0.01,P = 0.99).Moreover,when comparing the postoperative CTFS between group A and group B,the difference was not statistically significant(t= 1.38,P = 0.17).The mean postoperative ROM and OKS between the two groups were not statistically significantly different.Conclusion:Pre-operative coronal tibiofemoral subluxation can be corrected after UKA,and the outcome after UKA is independent of the degree of CTFS,and short-term follow-up shows that good results can be achieved with different degrees of preoperative tibiofemoral subluxation.